Carriage mechanism for typewriters



Nov. 17, 1959 H. L. THoLsTRUP 2,913,090

CARRIAGE MECRANISM RoR 'mxswRI'rRRs l Q 4mm/Ey- Nov. 17, 1959 H. 1.'1'HoLsTRUP 2,913,090

CARRIAGE MECI-IANISM FOR TYPEWRITERS Original Filed oct. 4. 195e IN V ENTOR. /fE/v/e y L //ozs mu y 147' 7 RA/EV Nov. 17, 1959 H. L. THoLs'rRuP2,913,090

CARRIAGE MECHANSM FOR TYPEWRITERS original Filed oct. 4, 195e esheets-sheet 4 IN V EN TOR.

Nov. 17, 1959 H. l.. THoLsTRUP 2,913,090

CARRIAGE MECHANISM FOR TYPEWRITERS original Filed oct. 4. 1956csheets-sneet 5 l fe) \\\KI'."

IN VEN TOR. Hf/vy Z. 79m .f7/MP H. A| .T||o|\ s'|-RUP 2,913,090 CARRIAGEMECHANISM FOR TYPEWRITERS original Filed oci. 4,1956 Y Nov. 17, 1.959

6 Sheets-Sheet 6 IN VEN TOR. #5A/R y l 7240i; new

United States Patent AO CARRIAGE MEcHANrsM Fon TYPEWRITERS Henry L.'Tholstrup, Rochester, N.Y., assignor to Commercial Controls Corporation,Rochester, N.Y., a corporation of Delaware` Orig'nal application October4, 1956, Serial No.

now Patent No. 2,900,065, Divided and this application No. 712,341

Claims. (Cl. 197-60) 613,900, dated August 18, 1959. January 31, 1958,Serial p Mechanism for Power Driven Printer, the power connectionbetween the drive mechanism and the type levers is such that the typelevers cannot be shifted byshifting the type basket between upper andlowercase positions. Itis, therefore, necessary to provide a specialplaten mounting carriage whichk provides for the shifting` of the platenbetween upper and lowercase printing positions.

It is, therefore, the principal object of this invention to provide acarriage structure for mounting the platen such'that the platen may beshifted between upper and lowercase positions in reference to a iixedtype impact point.

' It is a further object of the invention to provide power means inconjunction with the carriage structure for shifting the platen intoboth uppercase and lowercase positions.

These and other objects and advantages of the invention will becomeapparent from a reading of the following specification in reference tothe'drawings which form a part of this application, and in whichdrawings:

Fig. 1 is a side elevational view of acarriage mechanisrn in associationwith a power operated printer;

Fig. 2 is a horizontal view through the base of the carriage, taken online 2 2 of Fig. l, parts being broken away to show underlyingstructure;

Fig. 3A is a vertical sectional view through the carriage of theprinter, looking from the left and illustrating platen support andshifting mechanism at the right end of the carriage while the platen isin lowercase printing position;

Fig. 3B is a vertical sectional view on the same plane asthat'illustrated in Fig. 3A, Fig. 3B illustrating power transmittingmechanism in the base of the printer, and Figs. .3A and 3B togetherconstituting a continuation of the related mechanism at the right sideof the printer;

Fig. 4 is a View on the sarne plane as Fig. 3A, showing, however, theplaten shifted into uppercase position;

Fig. 5 is a view taken on line 5 5 of Fig. 4;

Fig. 6 is a view taken on line 6 6 of Fig. 4;

Fig. 7 is a fragmentary View of certain of the power transmittingmechanism shown in Fig. 3B, showing, however, the illustrated parts inthe position occupied during uppercase printing;

Fig. 8 is a sectional view on line 8 8 of Fig. 3B;

, Fig. 9 is a vertical sectionalv view on line 9 9 of Fig. 3B; K

Fig. 10 is a horizontal sectional view on line 10-10 of Fig. 9; and

Fig. l1 is a diagrammatic representation of the platen controlmechanism.

" ,A positive drive connection for the type levers requires that thetype basket be fixed in relation to the power transmitting system.Therefore, resort must be had to a system for printing upper andlowercase characters which is compatible with a xed type basket. Inprinters of the conventional typewriter category, the type basket isdisposed in an upper position for the typing of lowercase characters andis depressed to a lower position for the printing of uppercasecharacters. This arrangement, however, is not suitable in a machinehaving a fixed type basket; therefore, mechanism is provided hereinwhereby the platen may be` shifted upwardly for the typing of uppercasecharacters and returned to a lower position for the typing of lowercasecharacters. One form of mechanism for accomplishing these operations isillustrated in the drawings, and reference thereto will now be had inthe description that is to follow.

A carriage 10 constitutes the vehicle for a platen 12 and a paper rollholder 14. The carriage consists essentially of a base plate 16 (Fig. 2)having a pair of upstanding'end walls 18 and 20. Fixed in the end walls18 and 20 and located under the base plate 16 of the carriage are a pairof parallel guide rods 22 and 24. An identical pair of guide rods 26 and28 are iixed in the side walls of a base frame 30. The guide rods 22 28cooperate with a iioating carriage truck 32. The carriage truck 32 has apair of elongated bearing sleeves 34 adapted to receive and slide on thebearing rods 22 and 26, respectively, and a pair of shorter bearingsleeves 36, which are adapted to receive and slide on the bearing rods24 and 28, respectively. l

It will be seen, therefore, that the carriage truck 32 constitutes theconnection between the carriage 10 and the base frame 30 of the printer.As shown in Fig. 1, an escapement rack '38is iixed to the bottom of thecarriage frame and thereby controls the movement of the carriagetransverse of the printer frame 30. Movement Iof the carriage truck 32is controlled by a pair of sta.- bilizing tapes 40 and 42 which areeffective-to limit the transverse movement of the carriage truck 32 toone-half lthe distancetraversed by the-carriage 10. The stabilizing tape40 is trained about a pulley 44 attached to and extending laterally fromone face of the carriage truck 32, one end of the tape 40 being attachedto an anchor 46 iixed to the inner face of the printer frame 30- at oneside thereof, and the other end of the tape being fixed to the same sideof the printer by an anchor 48 located at the inner face of the endplate 20. In like manner, the tape 42 is trained about a pulley 50 txedto and extending from the opposite face'of the carriage truck 32, whileits respective ends arel also anchored to the opposite Wall of thetypewriter frame 30 by means of an anchor 52 and to the inner face ofthe end plate 18 by means of an anchor 54. From the foregoingdescription, it will be seen that as the carriage is reciprocated inrespect to the printer frame, the carriage truck 32 will slide in thesame direction on the guide rails 22-28, but this movement will belimited by the tapes to half the distance of carriage travel.`

The platen 12 is supported for rotation in a pair of identical platensupport plates disposed respectively adjacent the end walls 18 and 20 ofthe carriage on which end walls the respective plates are mounted foroblique movement in an up and down path, whereby the platen can beshifted between lupper and lowercase printing positions. Since theplaten support plates arev identical, their form and mounting may beobserved by reference to Figs. 4 6, wherein is illustrated a platensupport plate 56 which is associated with the carriage end wall 18y atthe right of the printer. -The platen support platesr are mounted bymeans of reciprocating guide structures, one of which is shown in Fig.5. In Fig. 4, lfor example, the platen support plate 56 has attachedthereto a pair 3 of brackets 58 and 60 in each of which is fixed adepending guide pin as, for example, a guide pin 62 associated with thebracket 60. These guide pins are adapted to slide in guide bearings 64and 64a which are mounted in the end wall 18 of the carriage. By meansof a pair of such guide structures associated with each of the platensupport plates, these plates are mounted for movement such that theplaten 12 can be raised for the typing of uppercase characters, as shownin Fig. 4, or lowered for the printing of lowercase characters, as shownin Fig. 3A.

The platen supporting plates are operated into their respective upperand lower positions by means of a linkage system, of which thatassociated with the platen supporting plate 56, is shown in Figs. 3A and3B. .lournalled in the side plate of the carriage 10, for example, is alever 66 which is capable of rocking about a mounting pin 68. The lever66 and the platen supporting plate 56 are operatively connected witheach other by means of a link 70 which has one end thereof pivoted tothe platen supporting plate 56 by means of a stud 72 while the other endthereof is pivoted to the lever 66 by means of a pin 74, which islocated slightly above and in front of the pivot 68 about which thelever 66 moves. This constitutes the lever 66 and the link 70, aneccentric device which is adapted to exert an operating force on theplaten support plate 56 which is generally parallel to the axis of theguide pins 62.

The lever 66 is connected to an actuating plate 76 by means of a link78. The actuating plate 76 is keyed to an upper shift-shaft 80 whichextends between the end plates of the carriage and is journalled thereinfor rocking movement. By reference to Fig. 4, it will be seen that whenthe shaft 80 is rotated in a clockwise direction, the actuating plate 76will pull the link 78 in a downward direction, thereby rocking the lever66 in a counterclockwise direction. This effectively elevates the platensupporting plate 56 to the position illustrated in Fig. 4 where theplaten 12 is positioned for uppercase printing. This is the position ofthe parts illustrated in Fig. ll which is a diagrammatic presentation ofthe mechanism involved for shifting the platen from one position toanother.

By reference to Fig. 11, it will be seen that the opposite end of theupper shift-shaft 80 has also keyed thereto an operating plate 82 whichserves thesame function as the operating plate. 76 but which has aconiiguration somewhat different by reason of the fact that while theplate 76 moves in one direction, the plate 82 must produce a motionwhich is effective in the opposite direction.

The operation plates 76 and 82, and consequently the upper shift-shaft80, are alternately moved from one position to another by means of apair of shift tapes 84 and 86 interconnecting the operating plates 76and 82, respectively with an intermediate shift-shaft 88 located in thebase of the printer. The intermediate shiftshaft 88 extends transverselyof the printer base and has its ends journalled in the side Walls of thebase, so that the shaft may be rocked from one position to another bymechanism shown in Figs. 3B, 7 and 8. In these figures, the intermediateshift-shaft 88 carries at each end generally similar mechanism forimparting rocking motion to the shaft. The mechanism shown in thefigures referred to is that located at the right side of the. printerwhich may be considered the mechanism for shifting the platen to itslowercase position. As stated, the mechanism at the left end of theintermediate shift-shaft 88 is generally similar and such differences asexist will be pointed out in reference to the diagrammatic View of Fig.ll; it being pointed out here that themechanism at the left side of theprinter is that which4 controls the rocking of the shaft 88 for shiftingthe platen mechanism into its uppercase printing position.

A bell crank shaft 90 has mounted at opposite ends 4 thereof platenshift bell cranks 92 which are identical. The lowercase shift bell crankof Fig. 3B will serve to disclose the structure.

These bell cranks are designed to transmit operating power to the shiftmechanism by means of an interconnesting link, such as a link 94associated with the lowercase bell crank '9 of Fig. 3B. The shift bellcranks are operated from a power shaft 96, as fully described in myabove-noted application for patent, and such operation is under controlof shift magnets, in all respects the same as more fully described insaid application.

Briey: a bell crank 92 is rocked about a bell crank shaft 90' by meansof a drive plate 98 fixed for rotation with the powerV shaft 9'6.Extending from one face of the drive plate 98 are a pair of drive pins100' and 102. These drive pins are adapted to cooperate with elements ofthe bell crank 92 to drive the bell crank through its operative stroke.By reference to Fig.` 3B, i t may be seen that the bell crank 92 carriesa bellV crank latch. 104,. a guide plate 106, a stop pawl 108 and a pairof lugs: 110 and 112. The bell crank latch 104 is pivoted on the bellcrank 92 by means of a pivot pin 114. The bell crank latch 104 is biasedabout the pivot pin 114. in aV clockwise direction (as viewed in Fig.3B) by means of a spring 116 which extends between the free end of thebell crank latch 104 and the bell crank 92. The bell crank latch 104 isnormally held in retracted position by a bell crank trip lever 118. Thebell crank trip lever 118 is pivoted on a trip lever shaft 120 aboutwhich it. is normally biased in a clockwise direction (as. viewed inyFig. 3B) by a spring 122 connecting the upper end of the bell crank triplever 118 with a casing 124 in which the bell crank assembly is located.The bell crank trip lever 118 is generally L-shaped and has an inwardlyextending leg 126, which at its free end has a downwardly extendingfinger 128, adapted to engage a latch point 130 at the lower end of thebell crank latch 104. While the finger 128 and the latch 130 areengaged, as shown in Fig. 3B,. the bell crank latch 104 will be in itsretracted position against the tension of the spring 116. The powershaft 96 is constantly rotated by a suitable electric motor and..

. therefore, the drive plate 98 also rotates constantly. So

long as the bell crank latch 104 is in its retracted position, the pinsand 102 of the associated drive plate 98 will rotate freely in respectto the bell crank 92. In this connection, it should be noted that thepins 100 and 102 extend into proximity with the face of the bell crank92A such that if the bell crank latch 104 is released, its lower freeend 130 will be engaged by either of the pins 100 or 102 with the resultthat the bell crank 92 will be driven in a clockwise direction (asviewed in Fig. 3B) about the bell crank shaft 90.

As the drive pin 102 (for example) is rotated ina clockwise direction,its contact with the free end of the bell crank 104 will result in aclockwise movement of the bell crank 92 about the bell crank shaft 90.This movement will continue until the slot formed between. lug 112 andthe end of the guide plate 106 coincides with the path of the drive pin102. At this moment, the drive pin 102 will enter the slot and passfreely to the point where it contacts the lug 110. When the lug isengaged by the drive pin 102, the segment 92 will be rocked back to itsoriginal position.

When the shift segment 92 is operated, the link 94will transmit power toa link 132 which is mounted for free rotation on the intermediateshift-shaft 88. Associated with the link 132 is a mechanism which-iskeyed to the intermediate shift-shaft 88 and which is adapted to rotatethe intermediate shift-shaft 88 when operated by the link 132. Thismechanism is, is effect, a flanged sleeve 134 (Fig. 8) which is keyed tothe intermediate shiftshaft 88 by means of a pin 136. The sleeve 134hasa pair of flanges projecting therefrom. A ange 138. is located inproximity to the link 132 and has a stud 140 projecting1 inwardly fromthe face thereof. The. stud' 140 lies in the vertical plane of the link132 and isadapted to register with a notch 142 (Fig. 3B) which is formedin the upper edge of the linf. 132. When the shift mechanism is in theuppercase position, the disposition of the elements just referred to issuch that the stud 140 rests in the notch 142 so that when the link 132is pulled forward by operation of the shift segment 92, the -sleeve 134and consequently the intermediate shift-shaft 88 will be rocked in acounterclockwise direction which is effective to lower the platensupporting mechanism into lowercase printing position.

When the intermediate shift-shaft 88 is rocked to its clockwiseposition, the shift tape 84 which is attached to a pin 144, carried by aange 146 atthe opposite end of the sleeve 134, will be pulled down withthe result that the actuating plate 76 of Fig. 3A will be rotated in aclockwise direction, thus rotating the shift-shaft 80 in a clockwisedirection to effect elevation of the platen support plates intouppercase printing position. When the shift segment 92 is operated, thelink 94 will be pulled forwardly with the result that the link 132 willengage the stud 140, if the stud is in its lower position at this time,thereby rocking the intermediate shift-shaft 88 in a counterclockwisedirection. This, in effect, relieves the tension on the shift tape 84and applies tension to the shift tape 86, as seen in Fig. 11. Tension ofthe shift tape 86 will rotate the plate 82 and consequently the uppershift-shaft 80 in a counterclockwise direction. The result of this isthat the platen support plates are lowered into lowercase printingposition.

The shift segment and associated mechanism for operating theintermediate shift-shaft 88 in a clockwise direction is in all respectsthe same as that described in connection with the lowercase shiftmechanism with the exception that a link 148 of Fig. ll, which is thecounterpart of the link 132 of Figs. 3B, 7 and 8 is oppositely mountedon the intermediate shift-shaft 88 and the link, corresponding to thelink 94, connecting it to the uppercase shift segment is extended to thefront of the intermediate shift-shaft 88 such that the link 148 ispulled about the intermediate shift-shaft 88 in a clockwise direction.

The fact that the shift tapes 84 and 86 each has an end thereofconnected to a point in the base of the printer which is fixed in thehorizontal direction and the other ends thereof connected to points inthe carriage, which is movable in a horizontal direction, demandsmechanism for keeping these tapes under constant tension at all times.The mechanism for the stated purpose is shown in the diagrammaticrepresentation of Fig. 11 and the detailed nature thereof is moreparticularly illustrated in Figs. 9 and 10. In Fig. 11, it will be seenthat the tension of the tape 84 is controlled by a pentagraph lever 150while the tension of the tape 86 is controlled by an identical lever152. As the carriage moves from right to left, for example, tension onthe tape 86 tends to increase while tension on the tape 84 tends todecrease. Compensation of this condition is provided by the relativeshortening of the pentagraph lever 152 and the relative elongation ofthe pentagraph lever 150. A consideration of these functions will becomeclear by reference to Fig. 10 which shows the details of the lever 150.

The lever 150, which is typical of both such levers employed, comprisesa long arm 154, which is pivoted on the base 30 of the printer and ashort curved arm 156, which is pivoted to the free end of the long arm154. The end of the short arm 156, which is distant from its connectionto the long arm 154, is pivoted to the underside of the carriage 10 bymeans of a pivot pin 158. The pivot pin 158 also supports a guide pulley160 directly under the adjacent end of the short arm 156. There is alsoa guide pulley 162 on a pin 164 which connects the arms 154 and 156. Apin 166 by means of which the arm 154 is mounted on the base ,30 alsosupports a guide pulley 168. The shift taper84 is trained upwardly fromthe pin 144 (Fig. 3B) about a series of guide pulleys including thepulleys 160,162, 168 and 170. This shift tape also passes about a guidepulley-.172

mounted on a pin 174 extending downwardly from the will first be shiftedto the right and as the printing ofa.- line proceeds, the `parts moveprogressively to the leftv and will assume the dotted line position ofFig. 10 by the time the carriage approaches-its left hand position. Astudy of Fig. 10 will indicate that as the arms 154 and 156 rotate abouttheir respective pivot points 166 and 158 into the dotted line position,the short arm 156 will assume an extended position in respect to thelong arm 154 and thereby maintain shift tape tension to compensate forchange of carriage position.

What is claimed is:

1. In a typewriter, a base structure having a pair of opposite sidewalls, a transverse guide track mounted in said side walls, a carriagehaving a pair of opposite end walls, a transverse guide track mounted insaid end walls, a truck having bearing surfaces embracing said guidetracks whereby said carriage is mounted on said base structure fortransverse movement in respect thereto, a pair of tape guides extendinglaterally in opposite directions from said truck, separate truck-controltapes trained about each of said tape guides, one of said tapes havingone of its ends fixedto one of said base side walls and the other end tothe adjacent carriage end wall, and the other of said tapes having oneof its ends fixed to the other of said base side walls and the otherlend to the adjacent carriage end wall. l

2. In a typewriter, a base structure having a pair'of opposite sidewalls, a pair of transverse guide rods mounted in said side walls, acarriage having a pair of opposite end walls, a pair of transverse guiderods mounted in said end walls, a truck having bearing surfacesembracing said pairs of guide rods whereby said carriage is mounted onsaid base structure for transverse movement in respect thereto, a pairof tape guides extending laterally in opposite directions from saidtruck, separate truck-control tapes trained about each of said tapeguides, one of said tapes having one of its ends fixed to one of saidbase side walls and the other end to the adjacent carriage end wall, andthe other of said tapes having one of its ends fixed to the other ofsaid base side Walls and the other end to the adjacent carriage endwall.

3. In a typewriter, a base structure having a pair of opposite sidewalls, a transverse guide track mounted in said side walls, a carriagehaving a pair of opposite end walls, a transverse guide track mounted insaid end walls in such position that the track is disposed in a planeparallel to said first named track and spaced therefrom in a verticaldirection, a truck having bearing surfaces embracing said pairs of guiderods whereby said carriage is mounted on-said base structure fortransverse movement in respect thereto, a pair of tape guides extendinglaterally in opposite directions from said truck, separate truck-controltapes trained about each of said tape guides, one of said tapes havingone of its ends fixed to one of said base side walls and the other endto the adjacent carriage end wall, and the other of said tapes havingone of its ends fixed to the other of said base side walls and the otherend to the adjacent carriage end wall.

4. In a typewriter, a base structure having a pair of opposite sidewalls, a pair of transverse guide rods mounted in said side walls, acarriage having a pair of opposite l, en'd walls, a pair of transverseguide rods mounted in said end walls' in such position that said guideYrods are disposed in a plane parallel to` said first pair of guide rodsand spaced therefrom in a` Vertical direction, a truck: havingbearing.surfaces embracing said pairs of guide rods whereby said carriage ismounted on said base structure for transverse movement in respectthereto, a pair of tape guides extending laterally in oppositedirections from said truck, separate truck-control tapes trained abouteach of said tape guides, one of said tapes having one of: its endsiixed to one of said base side Walls and the other endfto the adjacentcarriage end Wall, and the other of said tapes having one of its endsfixed to the other of said base side Walls and the other end to theadjacent carriage end wall.

5. In a typewriter, a base structure having a pair of opposite sideWalls, a pair of transverse 'guide rods mounted in said side Walls, acarriage having a pair of opposite end walls, a lpair ,of transverseguide rods mounted in said end walls,- a truck having a pair of bearingsurfaces each consisting. of a pair of sleeves embracing said pairs ofguide rods whereby said carriage is mounted on said hase strueturefortransverse movement in'` respect thereto, a pair of tape guidesextending laterally in: opposite directions from said truck, separatetruck-control tapes: trained about each. of said tape guides, one ofsaid tapes having one of its ends txed to one of said base side wallsand the other end to the adjacent carriage end wall, and the otherof'said tapes having one 0fits` ends fixed to the other of said baseside walls am1 the other end to the adjacent carriage end Wall.

No references cited.

